Hydrothelphusa goudoti (H. Milne Edwards, 1853)

Cumberlidge, N., Reed, S. K. & Boyko, C. B., 2004, Distribution patterns of the Malagasy freshwater crabs (Crustacea: Decapoda: Brachyura), Journal of Natural History 38, pp. 1133-1157 : 1147

Hydrothelphusa goudoti (H. Milne Edwards, 1853)

(figure 2C)

Thelphusa goudoti H. Milne Edwards, 1853: 212 . A. Milne-Edwards, 1869: 172, pl. 8, figure 4a, b; 1887: 135 (type locality: road between Bombetok and Antananarivo, Madagascar).

Telphusa goudoti de Man, 1892: 235 .

Potamon goudoti de Man, 1898: 434 .

Potamon (Potamon) goudoti Rathbun, 1904: 305–306 , figure 34, pl. 13, figure 10; Balss, 1929: 355.

Potamon (Geothelphusa) methueni Calman, 1913: 920 (type locality: Imerimandrosa , Madagascar).

Bottia goudoti Pretzmann, 1961: 164 , figure 3.

Gecarcinautes goudoti Bott, 1965: 338–339 , pl. 2 figures 6, 7; Cumberlidge, 1997: 585; 1998: 209.

Hydrothelphusa goudoti Cumberlidge and Sternberg, 2002: 56–59 , figures 1D, 3D, 4D, 5D, 6D, 7G, H, 8D, 9J–M, 11D, tables 1 –4.

Material examined. Madagascar: four males (cws 45.8, 37.1, 36.4, 34.7 mm) collected with H. madagascariensis ( FMNH 5720 ) .

Type locality. Madagascar. Thelphusa goudoti : road between Bombetok and Antananarivo . Potamon (Geothelphusa) methueni: Imerimandrosa , near Lake Alaotra , Toamasina Province (17°30∞S, 48°30∞E).

Distribution. Hydrothelphusa goudoti is found in streams, rivers and lakes in the north-western, central and south-eastern regions of Madagascar in Antsiranana, Antananarivo and Toamasina provinces (figure 2C). Figure 2C shows six different localities for H. goudoti , from the literature (Cumberlidge, 1997, 1998; Cumberlidge and Sternberg, 2002). Hydrothelphusa goudoti is found in five major river basins in three provinces between 13° and 24°S, from the Tsaratanana massifin the north, to the Marotsy River near Androkabe in the south-east. Hydrothelphusa goudoti is not known from either the north-western Province of Mahajanga or the western and southern Province of Toliara (except for the extreme south-east of this province), and there are no records from Fianarantsoa Province.

Remarks. Hydrothelphusa goudoti was described in 1853, the first freshwater crab described from Madagascar. Hydrothelphusa goudoti is characterized by its prominent post-frontal crest, smooth carapace texture, small epibranchial and exorbital teeth, and unusual carapace proportions: it has the widest, longest and most arched carapace of any species in this genus. The distinguishing differences between H. goudoti , H. agilis and H. madagascariensis are provided above.

Conservation status. Although H. goudoti is locally common in the central highlands of Madagascar and is offered for sale in the market in Antananarivo, it is still known from only a few localities, and its status is threatened ( table 1).